An ornithologist I think is generally thought of as someone who studies birds exclusively, as a career, for the science of the birds themselves. Thus, a dedicated birder who has a job (or may be retired or independently wealthy, although this was a little different many years ago when pretty much all scientists were independently wealthy), who spends all his spare hours, plenty of money, and may even be an authority on some particular subject, wouldn't be considered an onrithologist but would be considered a bird expert. Along the same lines, well-known studiers of birds, such as Lorenz and even Jared Diamond may not be ornithologists as their main interest is behavior, animal distribution, physiology etc and the birds they study are merely vehicles to understanding that aspect of science. Plenty of scientists, from zoologists to anatomists, are paid to study birds at some stage of their career, but that doesn't make them an ornithologist, although what the may be doing is onrnithology. And similarly an "amateur" may be involved in ornithological endeavours, studies or the like; and a zoology graduate student may take a job for a year helping an ornithologist with a study; neither are, yet, ornithologists.
But does it matter? Darwin was not an evolutionary biologist, as the discipline hadn't been invented then, Jesus wasn't a Christian, the Buddha wasn't a Buddhist, etc. But they all did significant things that lasted, and benefited and advanced the knowledge of their areas of interest. Seems OK to me, whatever they are called. And don't let anyone tell you just what about birding you should or shouldn't enjoy, or is fine to do. It's your life.
Cheers, and happy birwitching.
But does it matter? Darwin was not an evolutionary biologist, as the discipline hadn't been invented then, Jesus wasn't a Christian, the Buddha wasn't a Buddhist, etc. But they all did significant things that lasted, and benefited and advanced the knowledge of their areas of interest. Seems OK to me, whatever they are called. And don't let anyone tell you just what about birding you should or shouldn't enjoy, or is fine to do. It's your life.
Cheers, and happy birwitching.